Use of hot air in extracting fiber from vegetable tissues.



PATBNTED APR. 28, A1908 M. R. KENNEDY. V

PROM VEGETABLB TIssUBs.

ACTING FIBER APPLIOATION FILED JULY UNITED STATES PATENT OEEroE.

MICHAEL R. KENNEDY, or DANsvILLE, NEW YORK, AssIeNon To 'HIE NATIoNALs'rnAw PULP COMPANY, or NEW YORK, N. Y., A CORPORATION or SOUTH DAKOTA.

USE OF HOT AIR IN EXTRACTQNG FIBER FROM VEG-ETABLE TISSUS.

Specification of Letters Patent.

t Patented Apr1l28, 1908.

Application filed July 28, 1906. Serial No. 328,212.

To allwhom it may concern:

Be it known that I, MICHAEL R. KENNEDY, a citizen of the United States, of Dansville, county of Livingston, and State of New 5 York, have invented certain new and useful Improvements in the Use of Hot Airin Extracting Fiber from Vegetable Tissues, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

The present invention relates to processes of extracting fiber from straw &c. at high temperatures, in which a charge of the straw is lconfined ina closed receptacle or so-called cooker, with suitable chemical liquor, and

-hezted and agitated to facilitate the action r"of the, liquor upon the straw. Heretofore, saturated steam has been employed as the heating agent in such processes and ap aratus, being injected directly into the c osed receptacle, and through a Ijournal when a rotary was used, or into the ingredients conined therein; but Vthe condensation of `the steam adds a considerable proportion of Water to the chemical liquor, and operates during the process to gradually dilute the same, so as to materially impair its eHect on the straw.

It is the object of the present invention to obviate such ydilution of the liquor by the heating agent, which object is accomplished in the present invention by using heated air, or hot air mixed with steam, as the agent for heating, dissolving and bleaching the c'ontents of the cooker.. l

kThe heated air conveys no appreciable de grec of moisture into the cooker and does not therefore affect the chemicalI strength' of the liquor, while it heats the same in the desired degree when agitated therewith in the manner usual in such cookers. Superheated or saturated steam may be mixed with the hot air when desired.

'In supplying the liquor Ato the cooker it is very desirable to heat the liquor before it is ,delivered into the cooker, so as to avoid the loss of time required to heat the same in the cooker, andthus utilize the cooker the entire time, for treatment of the straw.

The li( uor when heated cannot be readily propelle from a tank to the cooker by means of a suction-pump (other systems arevery expensive temperate) as the vapor from the liquor destroys the vacuum in thepump, and

'55 I therefore employ pressure upon the surface -spray pipe d.

discharged from t of the liquor in the closed tank to propel the same into the cooker, preferably using heater air to produce such pressure. The pressure of heated air upon the liquor in the tank thus vserves to heat the tank at the saine time that it propels the liquor from the same.

The apparatus employed in practicing this`v process may be varied without departing from the invention, an illustration being shown in thc annexed drawing, in which a cooker and a liquor supply tank are shown in section in a diagrannnatic form.v

(1. designates the cooker, shown of globular form mounted on trunnions with gearing c for rotating the vessel to agitato the contents. A pipe (l is shown extended into one of the trunnions to deliver the liquor or heated air to the cooker, and tcrminatcd within the cooker by a spray pipe d". 'l`hc pipc is carried to a supply tank c into which a pipe q is extended and provided with cock g to supply air or steam under a pressure sullicient to drive the liquor into the cooker. A pipo li: and cock k are shown to lcod the tank with liquor as required.

A pi e h for heated air is shown conncclcd with t e pipe d close to thcy trunnions, and the pipes are provided with cocks d and h adjacent to their junction.

A Char 1reofstraw is shown in thc cooker, and the liquor k2 is supplicd thcrcto b closing the cock h', openingr the cock d, and cxcrting pressure upon tho liquor in thc tank to force it into the cooker, whcrc ii is thrown upon the charge in jets lro'm holcs in tho Such prcssurc is cxcrtcd by opening the cock y', and thc dischargc of liquor can be stoppcd when dcsircd, b v closing such cock. 'lhc cock d being thcn closed, hcatcd air may bc injcctcd into the cooker through the spray pipcs by opening` the cock L, tho cooker boing rotated to agitato the charge with thc. liquor and heated air.

The rise ol" temperature in the cookcr produces a steam pressure corresponding to suchftemperaturc, and when the accumulai vessel tends to risc above ortion of tho air may be e upper part ol" thc vessel, as by vent cock j, and an additional supply of air then injected. u

The original and additional supplies oll air are admitted to the cooker while it is revolvinghmd always beneath the charge under such pressure, a

- vention tractmgiber from straw 35 ture desired with a treatment, so as to effectually penetrate the Superheated steam be mixed 4amount of moisture, and thus weaken' the liquor but slightly, while the increased temperature greatly-increases the activity and y mvention thus maintains the desired heat without injuriously weakening theliquors employed.

1s process is applicable to wood-chips and rags, as well as to straw. I am aware that hot air has been used by diusion in an open tank to promote the fermentation of vegetable fibers, but such an operation of the hot air does not suggest the substitution'of It is evident that where air is used to heat the liquor in a tightly closed receptacle containing any water, as in the present process, the'water is vaporized and steam. is g chemical li uor. v l

Having tchus set forth the nature of the inwhat is claimed. herein is: 1. The improvement in the process of exwith chemical liquors at high temperatures, which consists. in

conininfr a char e of the straw with the requlred chemicall yth that of temperature, and w1t out the condensation of vapor and the weakening of the chemical li uor.

e improvement 1n the process o1c ex- @easel tracting liber from straw &c. at high temperatures, which consists in connin a charge of suitable chemical is heated With a small condensation of vapor and sli ht weakening of the liquor.

3.` Tie improvement in the process of' extracting fiber om straw at high tem erat'ures, which consists in charging a c osed cooker or receptacle with a charge of straw, placing the liquor required for treating such charge in a osed tank, forcing heated air into the Asaid tank, and propelling the liquor into the cooker by air pressure.

he improvement in the process of extracting fiber from straw at high temperauor thus heating the he reguired temperature withening the iquor.

T 1e improvement in the process of extracting fiber from straw at high tem )eratures, which consists in) charging a' closed cooker orl receptacle with a charge of straw, spraying the'hquorrequired for treating the straw upon the straw-1n the cooker, and inlecting a mixture of heated air and supereated steam into the cooker while the liquor and straw are agitated, and thus heating the mixture to the -required temperature withf slight weakening of the liquor. In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. A

Y MICHAEL` R.V KENNEDY. Witnesses: i

P. M. HAMMOND, (J1-IAS. H. UNvERzAGT. 

